Selected requirements on a sustainable nutrient management

Nutrients are a limited resource and call for management. A sustainable nutrient management strategy reintegrates nutrients in the environment without accumulating harmful substances above an acceptable level. In this study a methodology to assess the environmental compatibility was developed. For this assessment both the (i) enrichment of pollutants in the soils and (ii) the area specific nutrient demand of the crops were taken into account. The method considers, that products applied on soils also contain stable substances, and as a consequence the accumulation of pollutants diminishes. Additionally, it is considered, that increasing substance concentrations in the soil will lead to an increase of substance flows out of the soil by percolation, plant-removal (and erosion). In practice long term management strategies are restricted by the time span considered, the accepted accumulation of substances, the plants real needs and legal constraints. The rating of various goods can be made with the ratio of the added nutrients, considering the pollution criteria, the legal constraints and the plants real needs.